"I fight Harry Potter but the children love me.’’ As a film actor, Alan Rickman is known mainly for his bad guy character roles, including the evil Professor Snape at Hogwarts.

Rickman has waited until the final film to be interviewed.
I have too much respect for the younger readers for spoiling the twists. Even now that everything has been written, there are children who are half way though the saga, or have seen only the first films, because the last are too scary.

Did you know the secrets of Snape from the beginning?
When I first got the part I phoned Ms. Rowling because I needed some trace. We had a long talk. It remained a secret.

What memories over the past ten years do you have in playing Snape?
The start was exciting. I took great care in every aspect, both psychological and practical, of the character: the cut of the hair, the length of the dress robes, the make-up. Then, I would enter a strange routine. Every year I'd travel, I'd direct plays, spinning other stories and then, for seven weeks, I would wear black contact lenses, finding an old friend again and a part of myself.

Movie after movie, Daniel Radcliffe and the other young actors have become adults ...
A few months ago I went to see Daniel in a Broadway show [How to Succeed in Business Without Really Trying]. While he sang and danced, I thought of the 11-year-old boy who stared at me wide-eyed behind his glasses on the set [of the first film.] Now Daniel is an artist and a strong young man, he also introduced me to his girlfriend.

What do you think of David Cameron's Government against the use of minors in advertising?
The British know how to raise their children without the help of the Government. The Harry Potter novels are more useful than a law: they encourage kids to read, they teach for example that there are moral and political choices that you have to make in life, giving priority to the common good than to one's individual selfishness.